Outside drill pipe cutter



- Dec. 1, 1942. F. L. LETBUS 2,303,647

OUTSIDE DRILL PIPE CUTTER Filed 001;. 1; 1941 5 Sheets-Sheeil fl E m I fi l-gqg BY r V I ATT'OH/VE) Dec, 1, 1942. L. LE'BUS 2,303,347

ouTsiDE DRILL PIPE CUTTER Filed Oct. 15, 1941 5 Sheets-Sheet 2 ebzis I Dec. 1, 1942. F. L. LEBUS 7 2,303,647

I OUTSIDE DRILL PI'PE CUTTER Filed Oct. 15, 1941 5-Sheefs--Sl 1eet s.

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Dec. 1, 1942. ,F. L. LE BUS 2,303,647

OUTSIDE DRILL PIPE CUTTER Fiied Oct. 13, 194 1 5 Sheiets-het 4 as $6 24 f f j, v ;1; V g .1 J

. fl'Qiii/kifidd' INVENTOR.

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F. L., LE-BUS V OUTSIDE DRILL PI E CUTTER Filed Oct. 13, 1941 5 Sheets-Sheet 5 INVENTOR.

Patented Dec. 1, 194-2.

* anger? warren ostrich @UTSIDE BRILL PEPE'CUTTER Franklin L. Le Bus, Longview, Tex. Application @ctober 13, 1941, Serial No. 414,834.

(or. rel-c6) I 4 Claims.

pipe with an external cutter, a tracer string, in-

serted after the first contact, greatly facilitates subsequent contacts with the lost string.

It is the purpose of this invention to provide an improved external drill pipe cutter to be used in connection with a tracer string system for cutting out and removing drill pipe which has become lost or stuck in a deep well. In this connection, one of the objects of the invention is the provision of an external cutter which has an automatic spring action co-operatively related to other parts of the cutter whereby it will be impossible for the lift dogs to become fouled while lowering cutter or while out is being made.

Another object of the invention is the provision of a lift dog construction in which the lift dogs are of a floating type, giving more spring and flexibility with easier repair or replacement without riveting or welding.

A further object of the invention is the provision of a relatively thin and stronger construction of cage or element which contacts the cutter means, enabling the cage to be made larger inside for freer passage of tool joints.

The invention also provides a variation in structure which permits its operation on those types of drill pipe which have no elevator shoulder on which regular lift dogs may catch to lift the cut-off section of pipe.

Other important objects of the invention will become apparent from the following detailed description, taken in connection with the acconipanying drawings, and in the drawings:

Figure 1 is a vertical sectional view in elevation of the pipe cutter as lowered into a hole ready to cut, partly broken away, and illustrating a washover string and overshot guide connected to the tool;

Figure 2 is a view similar to that of Figure 1, and illustrating cutting position of the knives;

Figure 3 is a view similar to that of Figures 1 and 2, but showing the position of the parts after the pipe has been cut and ready to be taken from the well;

Figure 4 is a cross-sectional view on the line 44 of Figure 2;

Figure 5 is a side View of a ring which provides 55 floating support for the lift dogs and fingers and for carrying the shear plugs;

Figure 6 is a side View of the cage which contacts with the cutters;

Figure '7 is a vertical sectional view in elevation of a modified form' of the invention for use on external flush drill pipe, the device being shown in lowering position;

Figure 8 is a view similar to Figure '7, but showing cutting position of the device;

Figure 9' is a cross-sectional view on the line 5-9, Figure 8;

Figure 10is a view similar to Figures '7 and 8, illustrating the gripping and elevating position of the severed pipe; and

Figures 11 and 12 are views, respectively, of a drilled hole, Figure 11 illustrating either form of the invention in cutting position with a tracer string, and Figure 12' showing thecutter entering the hole for a secondc'ontact or cutting.

In Figures 11* and 12 are views, respectively, of a drilled hole and showing the invention in operation with a tracer string. The tracer string system is no part of this invention, but is shown for the purpose of making clear the invention. In Figure 11- is shown a drilled hole as the tracer string A' is being placed. The washover pipe B, carrying adrill pipe cutter C (which'may be either of the types of the invention herein claimed) is over the lost drill pipe P (which may also be either a flush joint or'regular joint pipe), and suspended from a rotary tableindicated at D. When the tracer string is lowered, the guide'G readily finds and follows lost string to the lower end where the guide G rests on drill bit E. The tracer string is left at maximum practical working height above the hole, so that when the drill pipe is cut at the point F and the drill pip and the tracer string sag into the cavity K, the tracer string will not settle below the rotary table. Figure 12 shows the drilled hole after pipe has been 'cut at the point F and removed and washout string with external cutter C is re -entering for another cutting contact. The end F of drill pipe has sagged away from center in the cavity K, but the tracer string at' the pointL is guiding the cutter C to the end F 'of the drillpipe.

In accordance with the remaining parts of the drawings, and having reference to Figures 1 to 6, inclusive, the tool consists of a main body 3 having a section 2 threadedly engaged therewith, the section 2 having a wash-over string of pipe indicated in part at I, threadedly engaged therewith. Also threadedly connected to the lower end of the main body 3 is an overshot guide [9, shown partly broken away.

Disposed in the interior of the body is a cage 6, shown in detail in Figure 6 and upon which is supported a spring 4, the upper end of the spring bearing against the lower end of the section 2. The cage is open at the top as indicated at 6a and is formed with the fingers 1 which are beveled on their lower ends at 1-11 to properly engage the knives or cutters II, the knives being pivoted to the body by the pins l|--a so that they may be swung into and away from cutting position with the pipe. The cage is also integrally formed with portions 1-?) which, as shown in Figure 6, have a key-way 7-0 and by means of a feather key '!d, welded to the body 3, the cage is prevented from rotating, relative to body 3.

Below the cage is a ring l3, termed the l ft dog retainer ring, and shown in detail in Figure 5. This ring has peripheral slots l and also slots 8. The slots l5 are for the purpose of seating the lower ends I1, which are hooked, of the lift dogs 8. The lift dogs in the form of construction shown bear against the lower end of the tool joint 5 and are allowed to move out against the inner wall of the body 3, permitting freer passage of the tool joints and eliminate trouble inc dent with the jamming of the tool or the bendin of the l ft dogs. The inner hooked portions of the lift dogs are flush with the inside of the ring H3. The slots l8 are for the purpose of carrying shear plu s l6. which plugs. after having been sheared off when the tool is in lowering pos t on, ma nta n friction between the ring l3 and the wall of the body 3 and prevent sna or iar in the o eration of the knife feed mechanism. In Fi ure 1 is shown the posit on of the cutters I when not in cutting position, being swung into the slots 9 which also provide means for nsertion of the shear plu s I6. into lace. Wall lu s l2, see Figure 2, prevent the lift dogs from rotat n In Fi ures '7 to 10, inclusive, is shown a modificat on of the cutter, as ada ted to ap lication on dr ll p n s wh ch have no elevator shoulder on wh ch the lift dogs 8 may catch. In this applicat on of he nventi n there is rovided in place of the li t do s 8. the wickered slips 20 and the fin rs 2 the lower ends of the fingers be ng seated n the l ft dog reta ner rin in the slots I5, as previously po nted out. In the place of the form of the ca e 6. shown in Figures 1. 2 and 3, fllme. is substituted a knife feed cyl nder and slin b l co b ned. Thi cvlinder. sh wn at 22*,

has a key 23 to ro a e the sli s 2!] for release purnoses, notch s 24 in wh ch set the upper ends of the sett n fin ers 22', also slots 25 in which en a e sc evm 26 to prevent the cvlinder f om ri in u wardly w th the body of th device while lowerin it to cutting position. The left-hand wickered sl s 20 screw upwardly to release position when the device is rotated to the right. The arrangement also includes a ring 21 which carries pressure from the spring 4 to the slips 2B or to the feed cylinder 22, as needed. The feed cylinder includes a beveled portion 28 to provide proper feeding action to the knives H. In this construction there is also provided a key 29 (see Figure 9) for rotating the feed cylinder with the body of the device. In Figure '7, in this modification, the cutter is shown in a lowering position, with the slips 20 in a high position, as

' in slipping over a tool joint 5--a of the shoulderless type. In Figure 8 the shear blocks l6 have been sheared off, by the engagement of the slips with the tool joint and elevating slightly, after which the tool is lowered a few inches for cutting. In Figure 10 the slips are shown in engaging position on the tool joint 5a for elevating.

The operation of both forms of the cutting tool or device are similar, and in the operation of the invention shown in Figures 1 to 6, inclusive, the cutter is lowered into the hole, in a position to shear of]? the plugs l6 and start cutting. The ring I3 bearing against the knives or cutters l I, causes the knives, bearing on the beveled ends 'i-a of the fingers 1 of the cage 6, to clear the tool joints when lowering. When the tool is elevated from this position, the lift dogs 8 transmit the thrust from the tool joint 5 to the ring l3 and shear off the plugs Hi. In Figure 2 the knives or cutting members ll, forced downwardly by the fingersl, force the knives in against the pipe P, and when the tool is rotated, cut the pipe. The fingers .1 rest on the lugs [2' as the pipe is elevated. The lift dogs 8 can be lifted out of the ways or seats in the retainer ring l3, for replacement or repairs. The fingers I, located by the feather key 1-d and the lift dogs 8 by the wall lugs l2 cannot get tangled up. The lift dog retainer ring [3 also includes longitudinal ways 14 and in use the lift dogs are retained in the ways and slots by the inside wall of body 3 without further fastening.

From the foregoing it will be apparent that the drill pipe cutter as portrayed in the drawings and described in the specification presents a practical and efficient tool for the purposes set out. In the presentation the walls of the cage are made larger inside, hence provide freer passage of the tool joints. Absence of a spring seat outside of the cage provides greater strength, and the key locating cage ensures perfect operation. The floating lift dogs permit of easier assembly and replacement with different length of parts or where parts become damaged or worn.

The device is suited to both forms of drill pipe, by the variations shown, as by the inclusion of the cylinder and slip bowl, pressure ring, and fingers, the flush joint drill pipe may be successfully handled.

The disclosure of the invention, however, is susceptible to modifications other than those shown and described, in keeping with the inventive thought of the invention, and which may be said to fall within the scope and meaning of the appended claims.

What is claimed is:

1. An external drill pipe cutter for use in connection with a tracer string system, comprising a main body with a section connected thereto at one end and providing means for connection of a washover string of pipe; an overshot guide connected to the opposite end of the main body; a cylindrical cage member having spaced, bevelended fingers within the main body, a plurality of pipe cutter members pivoted in the wall of the main body, a spring, said fingers engaging the 4 pipe cutter members to move the cutter members under action of the spring to a cutting position against a pipe; said cage members including a key-way for preventing its rotation in relation to the main body; a ring below the cage member having spaced slots and grooves, a plurality of spring lift dogs having hooked ends and seated in a floating position in the slots and grooves, shear lugs in certain of said slots in the ring, a recess in the main body for temporarily seating the lugs, the dogs contacting a joint of pipe and exerting a thrust on said ring, shearing off said lugs when the cutter is lowered over a pipe.

2. An external drill pipe cutter as claimed in claim 1, which includes a construction wherein the hooked ends of the lift dogs are flush with the inside of the ring and adapted to be moved outwardly against the inner wall of the main body for clearance of pipe joints or tool joints, the lift dogs being flexible;

3. An external drill pipe cutter as claimed in claim 1, said ring having-spaced slots and grooves for the reception and seating loosely therein of a plurality of pipe engaging spring lift dogs having hooked ends, the lift dogs being removably seated in certain of the slots and grooves and providing a flexible, floating relation with the ring, the ring being positioned below the cutter members and providing a positive means for holding said cutter members in position. v

4. An external drill pipe cutter comprising a main body with a section connected thereto at one end and providing means for connection of a. washoverstring of pipe; an overshot guide connected to the opposite end of the main body; a cylindrical member constituting a knife feed and .slip bowl combined and having a beveled and notched lower end; a ring above the cylindrical member, a spring seated on the ring, the lower end of the inside walls of said. knife-feed-slip bowl being tapered inwardly, the lower end of the outside of said walls including means to prevent the cylindrical member from moving upwardly; toothed slip members having a lower tapered end to engage with the tapered walls of the knife-feed-slip bowl; pipe cutters pivoted in the wall of the main body to be engaged by the cylindrical member under action of said spring; 

